Weddell seal feeds on Adélie Penguins in the Ross Sea, Antarctica

Abstract

In the Antarctic ecosystem, leopard seals are known to be a main predator of penguins, while Weddell seals typically feed on fish and small crustaceans. In this study, we describe the observation of a Weddell seal that hunted juvenile Adelie Penguins on Inexpressible Island in the Ross Sea, Antarctica. The Weddell seal remained in the water near the edge of the sea ice and attacked young individuals. The penguins were in the late phase of molting and appeared to just venture into the water, which indicates that the individuals were unfamiliar with the water and had lower swimming ability than adults. To the best of our knowledge, this is the first video recording of Weddell seal predation on penguins and the first record on Adelie Penguins being attacked by the Weddell seals. Here, we discuss the possibility that Weddell seals could be an opportunistic predator of juvenile penguins when they are highly vulnerable.